PWM Acquisition trigged by external signal

[OPR31]

Hello.

The goal is to make acquisition of a position sensor PWM signal (500 Hz, duty cycle 10-90%).

An external signal (pulse) is sent by a motor controller in move  each x mm (typ. val x =0.02 mm).

I need to make a measurement (high level time & low level time) at each pulse, considering motor is moving continuously (typ. Speed = 30 mm/sec).

Board used : PCIe 6363

Dev software : Labwindows/CVI 2013 (any help in labview is welcomed too )

I succeeded in making a PWM Meas with a task CISemiPeriodChan, but not triggered with external signal, so I loose the position of each measurement.

Another solution may be another signal create (with another ctr) to “gate” measurement , but I did not succeed.

I have tried a lot of solution and samples, read a lot of post in forum without an working answer to my problem.

If someone could help me.

Thank you

[Valentin.B]

Hi bicoun,

Did you try to use the DAQmxCfgDigEdgeStartTrig ?

Your device support this property:

NI PCIe-6363 Supported Properties

You can also take a look at the analog measurement (voltage) examples which use this function.

Regards,